Boot the Rescue from the DVD. This should be the same Arch as the installation: ie; 32 bit or 64 bit..


Once the DVD rescue gets to 'login', type: root
from there I run fdisk -l to confirm my HD partitition order.
We need to mount root (for me that's sda3)

Now mount / (sda3) with:

mount /dev/sda3 /mnt

To mount the other devices
Next do:

mount --bind /dev /mnt/dev

Then chroot:

chroot /mnt

mount /proc

mount /sys

Your prompt changes to: Rescue:/>
Here type:

grub2-mkconfig -o /boot/grub2/grub.cfg

grub2-install /dev/sda

You can see it all here: https://dl.dropbox.com/u/10573557/Gr...ect/rescue.jpg

'exit'
# reboot

If you use LVM please check this post: https://forums.opensuse.org/vbcms-comments/478290-article-re-install-grub2-dvd-rescue-3.html#post2519005

N.B: This method should also work from a live cd
This should be the same Arch as the installation: ie; 32 bit or 64 bit..USE LIVE CD TO RESCUE

Quelle: https://forums.opensuse.org/content.php/128-Re-install-Grub2-from-DVD-Rescue